NEW ORLEANS -- University of Michigan scientists have used an insulin-like growth factor called IGF-I to stimulate growth of a myelin membrane sheath, similar to a sausage casing, around neurons in a culture dish.
"This is the first evidence to indicate that IGF-I can promote growth of new peripheral nervous system myelin sheaths," according to Eva L. Feldman, associate professor of neurology at the U-M Medical School.
If U-M scientists are able to use IGF-I to regenerate myelin in animals, it will be extremely significant; because without myelin, neurons cannot transmit signals from the brain to peripheral nerves or from nerves back to the brain.
Feldman and U-M research fellow Hsin-Lin Cheng presented the first results from their experiments with IGF-I at the Society for Neuroscience meeting here today (Oct. 27). James W. Russell, lecturer in neurology at the U-M Medical School, is a co-investigator on the project.
Because they stimulate growth of nerves, bone and muscle tissue, growth factors have been the subject of intensive research for the past decade. Scientists believe understanding how growth factors affect neural development could lead to new treatments for neurodegenerative diseases like diabetic neuropathy, multiple sclerosis and amyotrophic lateral sclerosis (ALS). The devastating symptoms of these diseases are caused by the death or degeneration of peripheral nerves. Although several growth factors are currently under study, IGF-I appears to be most effective at inducing myelination and preventing neural cell death, according to Cheng.
Named for its structural similarity to insulin and its ability to simulate insulin's glucose-lowering properties, IGF-I is produced in the liver and is present in blood serum. During embryological development, IGF-I
Contact: Sally Pobojewski
University of Michigan